Conductor stringing running board



Dec. 7, 1965 R. G. DOEL ETAL CONDUCTOR STRINGING RUNNING BOARD 5 Sheets-Sheet 1 Filed Dec. 16, 1963 Dec. 7, 1965 R. G. DOEL ETAL 3,222,033

CONDUCTOR STRINGING RUNNING BOARD Filed Dec. 16, 1963 5 Sheets-Sheet 2 Dec. 7, 1965 R. G. DOEL ETAL CONDUCTOR STRINGING RUNNING BOARD 5 Sheets-Sheet 5 Filed Dec. 16, 1963 p \l la -J 5/ R. G. DOEL ETAL CONDUCTOR STRINGING RUNNING BOARD Dec. 7, 1965 Filed Dec. 16, 1963 5 Sheets-Sheet 4 Dec. 7, 1965 R. G. DOEL ETAL CONDUCTOR STRINGING RUNNING BOARD 5 Sheets-Sheet 5 Filed Dec. 16, 1963 United States Patent F 9 Claims. 61. 2s4-134.3)

The present invention relates to so-called running boards used for the stringing of electric conductors on poles or towers. Pulley blocks, known as travellers, are mounted on the towers and a running board is drawn through the travellers by a pulling cable. The electrical conductors to be strung are in turn drawn through the traveller by the running board. It is important to handle the electrical conductors carefully to avoid scratching of their surfaces or the formation of kinks, either of which irregularities could result in sharp edges at which corona discharge would be likely to occur.

The technique for stringing electrical conductors from tower to tower is to suspend a traveller from an insulator on each tower, to thread a pulling cable through the series of travellers and to draw the pulling cable through by means of a winch. A running board is attached to the pulling cable, and the electrical conductors are attached to the running board. The conductors are maintained under suitable tension by braking of the reels from which they are unwound. With large conductors being strung through a series of towers spaced apart substantially from each other over a distance of perhaps 3 miles, comparatively large forces are exerted on the running board and the travellers. The running board must pass through each of the travellers, and it is important to minimise the frictional forces set up.

Desirably travellers should also include separately mounted and rotating sheaves for each of the electrical conductors as well as an independent sheave for the pulling cable. It is desirable to run the pulling cable in a separate sheave since the pulling cable might possibly damage the sheaves through which the electric cables are run and thus cause damage to the electrical cables themselves. The pulling line normally has a certain amount of dirt and lubricant on it which would contaminate the electrical cables. Also, the sheave for the pulling line must carry a higher load than the conductor sheaves and would normally be formed of ferrous material which has a very highly polished finish in the line groove to reduce the coefiicient of friction between the pulling line and the pulling line sheave to allow for rotational slip of the pulling line when it is under tension. This also prevents the pulling line climbing out of the pulling line sheave groove due to the lay of the cable strands.

Preferably the sheaves which carry the electrical conductors should be provided with a molded elastomeric groove lining so that the electrical cables will not in any way be damaged or deformed.

It is also desirable that the running board should be so constructed as to offer a minimum of resistance to transit through a traveller.

Further problems arise with running boards in relation to their orientation relative to the traveller as they approach the same. A traveller on a tower where the trans mission line changes direction will be pulled sideways, away from the vertical hanging position, by the horizontal components of the pulling line tension, and consequently the traveller sheaves will not stand vertically. On the other hand the running board will tend to approach the traveller lying horizontally by reason of the tensions in the conductors and the vertically depending tail of the running board. As a result, the running board must twist 3,222,033 Patented Dec. 7, 1965 as it enters the traveller, and it is one of the objects of the present invention to provide a construction of running board which is adapted to function in this way, smoothly and reliably, and without adding appreciably to the line pull required.

At other times, the traveller hangs truly vertical but the running board becomes tilted, for example by a wind load, and again essentially the same problem arises.

There is also a tendency for the line pull to be increased at the moment the running board (the main body of which is basically flat and rigid) rides up onto and over the traveller sheave or sheaves, and it is another object of the present invention to provide a construction of running board having improved properties in this regard, namely minimisation of the increase of line tension on transit through a traveller.

Reference may be had to prior United States patent application Serial No. 330,856 filed December 16, 1963 for illustration of a traveller mounted on a tower during a conductor stringing operation and to the Canadian patent application filed concurrently herewith entitled Traveller for a disclosure of the construction of a traveller adapted to be used with the first form of running board now to be described.

In accordance with the objects of the present invention, the latter comprises a running board for stringing conductors including travel through a traveller having a plurality of grooved sheaves comprising (a) a rigid body having an undersurface portion ex tending uninterruptedly from front to rear,

(b) an articulated tail secured to the rear of said body to depend therefrom when the running board is oriented horizontally in use thereby to stabilize the running board against transverse tilting,

(c) attachment means for pivotal attachment of a plurality of conductors, said attachment means being mounted on said body at the rear thereof,

(d) and further attachment means for a pulling cable mounted on said body forwardly of said conductor attach ment means,

(e) all said attachment means being located beneath said body in such location that cable and conductor connectors secured thereto project downwardly below saidundersurface portion and below all the lowermost portions of said body to provide a substantially smooth transition between travel of the running board with the pulling cable running in a grooved sheave of a traveller and travel of the running board with said undersurface portion running on the sheave rims and travel of the running board with one or more conductors in said grooved sheaves.

It is to be understood that the running boards illustrated herein and described below are provided solely as examples of the inventive features, and that the invention in its broad scope is limited only bythe appended claims.

In the drawings:

FIGURE 1 is a sectional side view of a first form of running board taken on :I-I in FIGURE 2;

FIGURE 2 is an underside view of FIGURE 1;

FIGURE 3 is a section on III-III of FIGURE 1;

FIGURE 4 is a side view of the running'board of FIG- URES l to 3 in use, showing it approaching a traveller;

FIGURE 5 corresponds to FIGURE 4 a short time later;

FIGURE 6 shows the same parts a moment later;

FIGURE 7 shows the same parts at a still later time;

FIGURE 8 is a view on VIIIVIlI in FIGURE 5;

FIGURE, 9 is a plan view of a second construction of running board;

FIGURE 10 is a front view taken on X-X of FIG- URE 9;

FIGURE 11 is a section on XI-XI of FIGURE 9;

FIGURE 12 is a section on XIIXII of FIGURE 9; and

FIGURE 13 is a view showing the running board of FIGURES 9 to 12 passing over a traveller.

The body 9 of the running board of FIGURES l to 8 comprises a main plate 10 and an under plate 11 that is recessed at 12 and curves upwardly and backwardly from a nose portion 8 to form wing portions 13 which extend rearwardly and outwardly from the nose portion 8 and present forwardly facing, smooth curved, convex surfaces. Along the trailing edge 6 of the body 9 the plate 11 has secured to it a spaced-apart array of brackets 14, 15, 16, 17 and 18. These brackets serve to interconnect the trailing edges of the two plates 10 and 11. Also the two outer brackets on each side (14, 15, 17, 18) furnish holes to receive pins 19 by which conductors 20 are connected to the running board through the agency of cylindrical swivelling connectors 21 and ferrules 22. Connectors 21 contain internal bearing-mounted swivels that permit the conductors 20 to rotate to any extent about their own axes. The central bracket 16 provides, at its trailing edge, an attachment point for an articulated tail 7, having the first tail section 23 connected to the bracket 16 by a pin 24. At its leading edge the bracket 16 provides an attachment point (pin 26) for a swivel connector 25 of the pulling cable 27. Connector 25 similarly permits the cable 27 to twist. Pins 19 and 24 are coaxial, and all the pins lie in a common plane which is situated at a comparatively low level in the device, as will be more fully explained below.

It is also important to note that pins 24 and 26 are comparatively close together by virtue of the positioning of pin 26 at a rearward location in the device. The functional significance of this feature will also be explained below. The pulling cable 25 lies in the recess 12, as perhaps best appreciated from FIGURE 8.

The tail 7 consists of four tail sections 23 articulated to one another by links 28 and each having a broad, fiat under-surface 29. The number of tail section can be varied as required.

FIGURES 4 to 8 show the cooperation between the running board and a traveller 30 which consists of a frame including side plates 31 and five sheaves, 32 to 36 arranged side by side on bearings supported on a shaft 37. The centre sheave 34 is adapted to receive the pulling cable 27, as shown in FIGURE 4, before the running board reaches the traveller. The tail 7 hangs down freely from its pivotal connection at pin 24 during this time. When the running board reaches the traveller its underneath surface 11 engages the rims of the sheaves, as shown in FIGURES and 8, while the connector 25 lies partly in the groove 34a in the sheave 34 and partly in the recess 12 of the body 9. The connector 25 may rest on the bottom of the groove 34:: or may be slightly lifted away therefrom by the engagement of the underside of the body with the sheave rims. In either case there will be only a very small amount of lifting of the running board as it traverses the traveller, and what lifting there is will be gradually applied. As the enlarged spliced and taped end 27a of the cable 27 enters the groove 34a (FIGURE 4) there will be a slight lifting of the running board. It will be appreciated that any lifting will temporarily increase the pulling line tension, and it is thus desirable to keep lifting to a minimum and to ensure that any lifting that is unavoidable is applied smoothly and gradually.

In prior constructions of running boards the pulling line swivel has been connected to the nose of the running board in such a position that the undersurface of the swivel is substantially coplanar with the undersurface of the running board itself. When such a running board passes through a traveller, an appreciable lifting takes place, because the undersurface of the running board has to be elevated from the level of the bottom of the groove in the pulling line sheave to the level of the rims of the traveller sheaves. This disadvantage is avoided in the present construction by so connecting the pulling line connector to the running board that such connector projects downwardly from the undersurface of the running board by an amount approximately equal to the depth of the groove 34a in the pulling line sheave 34. In this way little or no change in the elevation of the running board takes place when, on transit through the traveller, the Weight of the moving assembly is transferred from the sheave groove to the sheave rims. In the same manner, the lining up of the pulling line connector 25 with the conductor connectors 21, as far as their vertical dispositions are concerned, ensures a smooth and comparatively shockfree return of the weight of the moving assembly to the grooves of the conductor sheaves (FIGURE 7).

FIGURE 6 shows conditions when the bracket 16 which forms a rigid portion of the running board interconnecting the centre-lines of the pulling pivoted attachment (pin 26) and the transverse axis defined by the conductor pivoted attachments (pins 19) has progressed to a position mid-way through the traveller. The horizontal distance X between pins 26 and 19 is an important factor in the improved performance of the present construction. In general, the shorter this distance X is, the better, although it must not be zero. If it were zero, there would be no tension transmitted in a front to rear direction through the running board and hence no force to maintain the running board properly oriented. In practice the lower limit of this distance will be determined by manufacturing considerations and the need to allow the various parts to pivot without fouling one another. The maximum value for the distance X will be that which ensures that the conductor swivel connectors 21 will enter their sheave grooves, before the pulling line swivel connector 25 has left its groove. A connector will be considered as being in its associated groove whenever it is below the rim of the sheave, because in this condition it prevents sideways displacement of the assembly relative to the traveller. FIG- URE 6 has been used to demonstrate approximately this maximum value for X by the hatched areas 25a and 21a. In practice the area 21a must have become appreciable (enough to check any sideways displacement of the running board) before area 2511 disappears or becomes too small for this purpose. Obviously some overlap as a safety factor will be desirable. A practical distance for the dimension X will be of the order of 4 inches.

The curved wing portions 13 are so shaped that the running board will be smoothly guided into the traveller, even if, as they come together, there is a relative tilting between the running board and traveller for one of the reasons mentioned above. The smooth uninterrupted undersurface of the running board from front to rear also contributes to the smoothness of a transit and to the avoidance of line shocks.

The running board body 9 finally passes beyond the traveller (FIGURE 7). The lower surfaces of the brackets, 14, 15, 17 and 18 will by this time have guided the connectors 21 and hence the four conductors 20 into the grooves of the four outer sheaves 32, 33, 35 and 36 of the traveller. At this time the tail sections 23 travel smoothly over the sheave rims until the entire tail has moved beyond the traveller. Surfaces 38 on the adjacent ends of the tail sections prevent reverse pivoting of the tail sections relative to each other, and stop 39 (FIGURE 1) on the first tail section abuts plate 10 to prevent the entire tail pivoting upwardly beyond the position shown in FIGURE 1. By means of the various features described, a very smooth transit is achieved and the extra loadings resulting from lifting of the running board through the traveller are kept small.

The second construction of running board body 40 shown in FIGURES 9 to -13 has the same essential features as the body 9. It also consists of a pair of plates 41, 42 made to form curved, leading edges in the form of swept back wing portions 43. The lower plate 42 is tapered downwardly and inwardly to form a shallow V and conform to the shape of a complementary sheave 44 (FIGURE 13) of a traveller 45. As in the first construction, the point of attachment 46 for the cable connector 47 (FIGURE 13) is set well back in the device, such connector nesting in a recess 48 formed in the plate 42. Attachment 46 forms the leading end of -a bracket 49 which joins together the plate 41, 42 and terminates in an attachment 50 for the tail, which is not shown in FIGURES 8 to 13, but which may conveniently be the same as the tail of the first construction. Further brackets 51 and 52 secured to the rear side edges of the plate 41 provide attachment points for the conductor connectors 53 (FIGURE 12), and in this construction the critical horizontal spacing is between the pivot pin sockets provided by attachment 46 forwardly and attachments 51 and 52 rearwardly. The pulling cable 54 runs in a groove 55 of the sheave 44. On transit through the traveller 45, the running board rides very slightly up in the manner shown in FIG. 13, with its V shaped undersurface placing the weight of the moving assembly on the V surface of sheave 44 and automatically centering itself with respect thereto. Finally, the conductors 53 are guided into the grooves in the outer sheaves 55 and 56, in a like manner to that already explained in connection with the first construction.

We claim:

1. A running board for stringing conductors including travel through a traveller having a plurality of grooved sheaves comprising (a) a rigid body having an undersurface portion extending uninterruptedly from front to rear,

(b) an articulated tail secured to the rear of said body to depend therefrom when the running board is oriented horizontally in use thereby to stabilize the running board against transverse tilting,

(c) attachment means for pivotal attachment of a plurality of conductors, said attachment means being mounted on said body at the rear thereof,

(d) and further attachment means for a pulling cable mounted on said body forwardly of said conductor attachment means,

(c) all said attachment means being located beneath said body in such location that cable and conductor connectors secured thereto project downwardly below said undersurface portion and below all the lowermost portions of said body to provide -a substantially smooth transition between travel of the running board with the pulling cable running in a grooved sheave of a traveller and travel of the running board with said undersurface portion running on the sheave rims and travel of the running board with one or more conductors in said grooved sheaves.

2. A running board according to claim 1, wherein (f) said attachment means (-c) are distributed across the rear of said body in an alignment defining a transversely extending conductor pivoting axis,

(g) and said further attachment means ((1) is located a positive distance forwardly of said axis,

(h) said distance being sufficiently short that, during transit through a traveller, a connector secured to said attachment means (c) will commence to enter a sheave groove before a connector secured to said attachment means ((1) is fully withdrawn from a sheave groove.

3. A running board according to claim 1, including a recess in said body to receive a connector securing a pulling cable to said further attachment means ((1).

'4. A running board according to claim 1, (f) wherein said body includes wing portions extending rearwardly and outwardly from the nose portion, (g) said wing portions having forwardly facing,

smoothly curved, convex surfaces. 5. A running board according to claim 1, '(f) wherein said tail comprises a plurality of sections and means articulating said sections together such that each section can turn freely to a depending position about the next more forwardly situated section, when such last-mentioned section is held horizontal, but cannot turn oppositely to rise substantially above the horizontal,

(g) and means pivotally mounting the most forwardly situated tail section to said body such that said last mentioned section can turn freely to a depending position from said body, When the latter is held horizontal, :but cannot turn oppositely to rise substantially above the horizontal.

6. A running board according to claim 1,

(f) wherein said body includes an undersurface that tapers downwardly from the sides to the centre to form a shallow V to cooperate with a complementarily shaped broad central sheave of a traveller.

7. In combination,

(a) a traveller comprising a plurality of grooved sheaves mounted side-by-side,

('b) a running board for stringing conductors by transit through said traveller and having an undersurface portion extending uninterruptedly from front to rear,

(c) said running board having a rigid body and an articulated tail secured to the rear of said body to depend therefrom when the running board is oriented horizontally in use thereby to stabilize the running board against transverse tilting,

(d) a plurality of attachment means mounted on said body at the rear thereof in an alignment defining a transversely extending conductor pivoting axis, and a plurality of connectors connected each to a respective attachment means for connecting a respective conductor to such means,

(e) further attachment means mounted on said body forwardly of said attachment means (d), and a connector connected to said further attachment means for connecting a pulling cable thereto,

(f) each said connector projecting below said undersurface portion by an amount substantially equal to the depth of the groove in the traveller sheave with which said connector is positioned to cooper-ate to provide a substantially smooth transition between travel of the running board with the pulling cable connector running in a sheave groove and travel of the running board with said undersurface portion running on the sheave rims and travel of the running board with the conductor connectors running in grooves of said sheaves.

8. The combination of claim -7, wherein said further attachment means is located a positive distance forwardly of said axis, said distance bein-g' sufiiciently short that, during transit through said traveller, the connectors secured to said attachment means (d) will commence to enter the sheave grooves with which they cooperate before the connector secured to said further attachment means (e) is fully withdrawn from the sheave groove with which it cooperates.

9. The combination of (a) a traveller comprising a plurality of grooved sheaves mounted side-by-side,

(b) a pulling cable engaging a generally centrally positioned one of said sheaves and terminating in a swivel connector,

('c) a plurality of conductors each terminating in a swivel connector,

(d) and a running board interconnecting said connectors and having an undersurface portion extending uninterruptedly from front to rear,

(e) said running board having a plurality of rearwardly positioned attachment means each connected to a conductor connector and spaced apart across the running board to locate each conductor in register with a traveller sheave located laterally of said pulling cable sheave,

(f) said running board further having an attachment means connected to said pulling cable connector,

(g) said last-mentioned attachment means being posion the rims of the sheaves and travel of the running tioned forwardly of the rearwardly positioned attachment means by a positive distance sufficiently short that, during transit through said traveller, the conductor connectors will commence to enter the sheave grooves with which they cooperate before the board with the conductor connectors running in respective grooves of the sheaves.

References Cited by the Examiner UNITED STATES PATENTS pulling cable connector is fully withdrawn from the sheave groove with which it cooper-ates,

(h) each said connector projecting below said undersur-face portion by an amount substantially equal to 10 the depth of the sheave groove with which it cooperates to provide a substantially smooth transition between travel of the running board with the pulling WILLIAM FELDMAN Prima Examiner cable connector running in a groove and travel of the ry running board with said undersurface portion running 15 MILTON S. MEHR, O. M. SIMPSON, Examiners.

4,676,584 7/1928 Tideman. 2,503,814 4/1950 Flager.

FOREIGN PATENTS 1,080,382 5/1954 France. 

1. A RUNNING BOARD FOR STRINGING CONDUCTORS INCLUDING TRAVEL THROUGH A TRAVELLER HAVING A PLURALITY OF GROOVED SHEAVES COMPRISING (A) A RIGID BODY HAVING AN UNDERSURFACE PORTION EXTENDING UNITERRUPTEDLY FROM FRONT TO REAR, (B) AN ARTICULATED TAIL SECURED TO THE REAR OF SAID BODY TO DEPEND THEREFROM WHEN THE RUNNING BOARD IS ORIENTED HORIZONTALLY IN USE THEREBY TO STABILIZE THE RUNNING BOARD AGAINST TRANSVERSE TILTING, (C) ATTACHMENT MEANS FOR PIVOTAL ATTACHMENT OF A PLURALITY OF CONDUCTORS, SAID ATTACHMENT MEANS BEING MOUNTED ON SAID BODY AT THE REAR THEREOF, (D) AND FURTHER ATTACHMENT MEANS FOR A PULLING CABLE MOUNTED ON SAID BODY FORWARDLY OF SAID CONDUCTOR ATTACHMENT MEANS, (E) ALL SAID ATTACHMENT MEANS BEING LOCATED BENEATH SAID BODY IN SUCH LOCATION THAT CABLE AND CONDUCTOR CONNECTORS SECURED THERETO PROJECT DOWNWARDLY BELOW SAID UNDERSURFACE PORTION AND BELOW ALL THE LOWERMOST PORTIONS OF SAID BODY TO PROVIDE A SUBSTANTIALLY SMOOTH TRANSITION BETWEEN TRAVEL OF THE RUNNING BOARD WITH THE PULLING CABLE RUNNING IN A GROOVED SHEAVE OF A TRAVELLER AND TRAVEL OF THE RUNNING BOARD WITH SAID UNDERSURFACE PORTION RUNNING ON THE SHEAVE RIMS AND TRAVEL OF THE RUNNING BOARD WITH ONE OR MORE CONDUCTORS IN SAID GROOVED SHEAVES. 